Apparatus for making plaster-board.



H. S. HEICHERT.

APPARATUS FOR MAKING PLASTER BOARD. APPLICATION FILED JUNE 1, 1909.

Patented Apr. 23, 1912.

2 SHEETS-SHEET 1.

H. S. HEIOHERI. APPARATUS FOR- MAKING PLASTER BOARD.

APPLICATION FILED JUNE 1, 1909.

Patented Apr. 23, 1912.

2 SHEETSSHEET 2.

UNITED STATES ATENT OFFIC HERMAN S. HEIGI-IERT, F FORCD CITY,PENNSYLVANIA, ASSIG-NOR TO PITTSBURGH PLATE GLASS COMPANY, OFPITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

I APPARATUS FOR MAKING PLASTER-BOARD.

Specification of Letters Patent.

Patented Apr. 23, 1912.

To all whom it may concern:

Be it known that I, HERMAN S. HEICHERT,

' a citizen of the United States, residing at Ford City, in the countyof Armstrong and State of Pennsylvania, have invented certain new anduseful Improvements in Apparatus for Making Plaster-Board, of which thefollowing is a specification.

This invention has reference to an im-. proved form of apparatus for themanufacture and continued handling of plaster board such as is used forthe construction of dwellings, and of other like products, madepreferably of a composition of plaster of Paris or calcined gypsum, asmall quantity of cement, wood fiber, and a sufiicient amount ofwater-there being sometimes used other ingredients, but most generallyin combination with those specifically enumerated.

This invention has to do further with the formation of plaster boardfrom materials of this kind, by means of what is called a fluid press orfluid pressure device, the substances being held in the press insuspension and forced into position to form the board by deposition upona suitable screening surface, through the action of air or other fluidpressure, the amount of pressure employed beiplg approximately 7 5pounds to the square inc The first of the objects of my presentinvention is the improvement of the press apparatus by the introductionof certain details of construction whereby a greater facility andcheapness of operation are secured and the employment and constructionof suitable cloth or other fibrous screening means adapted to be used inconjunction with wire screen and grating, and the construction ofimproved means for handling and renewing and taking care of the cloth,all as will more clearly appear from an examination of the accompanyingdrawings, wherein- Figure 1 represents in side elevation an apparatusembodying my improvement;

Figure 2 is another view in elevation oil the apparatus shown in Figure1;

Figure 3 is a detail sectional view on the line III-III of Figure 2;

Figure 4 indicates a detail of the constructioi of the cloth or muslincarrying means, an

Figure 5 is a small sectional detail indicating the relation of themuslin and other screening parts.

Referring now more particularly to Figure 1, it will be seen that I havetherein shown the press itself indicated at 6, provided with a hopper 7which holds the charge before it is discharged into the press throughthe admission valve or mixture inlet valve 8.

Above the hopper is a suitable pulp-holding tank 9 with inlet valve 10therefor, and adjacent the hopper is a water tank 11 shown on Figure 2,with water pipes 12 and inlet controlling valve 13 connecting by meansof the pipe 14 with the upturned discharge nozzle 15 within the press,through which the water is supplied to the interior of the press.

Referring now again to Figure 1, it will be observed that the press isprovided with the strain rods 16 adapted to strengthen and support theparts, and with a cross bar 17 formed in a kind of open frame upon whichrests a grating 18 the top of which latter is covered in turn by a finewire netting 19 adapted to form a support for the final screeningsurface or device which is preferably the muslin or cloth 20. As a meansfor raising and lowering the frame-work I provide the system of levers21 formed in toggle shape and connected to a piston rod 22 that isactuated by a piston within the cylinder 23, through the instrumentalityof suitable fluid pressure. The various parts last described are mountedupon structural work 24:, in position as indicated in Figures 1 and 2. vi

The muslin or cloth screen 20 is cut into sections or sheets asindicatedin Figure 1, and said sheets are provided at their corners withhooks 25 engaging suitable lugs 26 in carrying chains 27, as shownin'Figure 4. The cloth or muslin 20 is held tight by means of thecross-bar or rod 28 and the catch devices referred to, and being made100 thus in sections if any section wears out or becomes stopped up withplaster, or for other cause has to be removed, it can be taken out ofthe machine and a new one quickly substituted without the necessity ofinterfering with the action of the whole machine or for any length oftime stopping the operation in the manufacture of the board. Asindicated in Figure 1, I have shown four such muslin cloths carried bythe pair of chains 27 running around the pulleys 29, and the said chainsare provided with an adjusting device 30 designed to regulate andmaintain the tension of the same at all times. term cloth is used in itsgeneric sense to designate any and all kinds of sheets of interwovenflexible material capable of catching the solid particles whilepermitting the water to pass readily therethrough. As a means for movingthe'chain and attached cloth I provide a belt 31, and at some suitablepoint I arrange a cleaning brush 32 and a device 33 for spraying waterupon the muslin to clean out of the interstices thereof the deposits ofplaster.

In order to admit air to the chamber of the press I provide an air inletpipe 34 having,the controlling valve 35, and as a means for forcing thewater out of the pipe 14 and nozzle 15, I also provide a supplementalair pipe 36 controlled by the valve 37. The air inlet 36 alone could beused if desired. In order to get a more uniform distribution of thematerial upon the screening surfaces within the press I provide what Icall a deflector (indicated in Figure 3 by the reference numeral 38),said deflector having preferably four arms directed toward the cornersof the press,'said arms being located under four apertures marked 39, sothat when the material comes down through the supply pipe and isdischarged through the apertures 39 it will strike the deflector armsand be carried somewhat toward the corners of the press and thus insurea more uniform distribution upon the surface of the screening cloth.

The pressure within the cylinder 23 is of course to becontrolled by anysuitable valve mechanism conveniently located, and the operation of thedriving mechanism is also to be under control of the operator of themachine, through suitable levers or other clutch devices of well knownconstruction.

The operation of my improved mechanism is as follows:

A suitable mixture having been placed within the hopper 7 and insuficient quantity to form one board, the pulp valve 10 is closed, andthe valve 13 for admitting water to the press is opened, after which,and almost simultaneously therewith, the mixture inlet valve 8 is openedand then quickly closed, allowing the mixture to fall from the hopperinto the pressure chamber immediately after and during the time that thewater inflows, it being desirable, however,

It will be understood that the to have a small amount of water admittedfirst to spread over the surface of the muslin which is in positionunder the pressure chamber and has been raised up into place by theupward movement of the toggles 21 and the cross-frame 17, the smallamount of water first admitted serving to distribute the mixture moreevenly and form a more uniform thickness of board. After the mixture hasfallen from the hopper into the chamber, and the valve 8 has beenclosed, the air inlet valve 35 is opened, allowing the pressure to comein on top of the mixture and water in the pressure chamber and drivingthe water down through the screening apparatus, depositing the solidmatter upon the upper surface of the muslin cloth 20 which is inposition in the machine. When the water is all pressed through, the airvalve is closed and what air is in the machine is allowed to escape,after which the pressure in the cylinder 23 is removed and thecross-frame 17 descends, freeing the board that has been formed upon theupper one of the muslin sheets 20 and allowing the movement of the clothscreen carried by the chains 27, which is now instituted, to carry .theboard laterally along out of the press,

and onto an adjoining conveying apparatus not here shown.

Having thus described my invention and illustrated its use, what I claimas new and desire to secure by Letters Patent, is the following: 7

' 1. An apparatus for forming plaster board and the like, comprising, apressure chamber, a foraminous screen therebeneath, a carrier movableover the screen, and a se-.

ries of removable clot-h screens detachably secured to the carrier.

2. An apparatus for forming plaster board, comprising in combination, apressure chamber, a screening device at the bottom of said pressurechamber, means for supplying mixture to said pressure chamber,

and a fixed battle member above the screening dev'ice for receiving andspreading the mixture.

3. A movable screening device for plaster board forming apparatus,comprising in combination, a pair of traveling or advanceable chains,and a series ofmuslin or cloth screening parts secured upon said chains,

substantially as described.

4. An apparatus for forming plaster board and the like, comprising apressure chamber, a screening device at the bottom of the chamber, crossarms above the screening device, and a pi. e thereabove for admittin"the mixture or form? 1g the article, said pipehaving at its lower endlateral openings arranged to discharge the mixture onto the said arms.

5. An apparatus for formin laster board and the like comprising, a fixedpres.

sure chamber provided with a reciprocable signed my name in thepresenceof the two foraminous bottom xlrliembeg, rlrlieargs for supsubscribedwitnesses. plying pressure to t e sai 0 am er, power means for raisingthe said bottom member; HERMAN HEIGHERT' 5 and a cloth screen mountedfor movement Witnesses:

over the said bottom member. HARVEY L. LECHNER, In testimony whereof Ihave hereunto ARCHWORTH MARTIN.

